During the lifetime of a patient, it may be necessary to perform a joint replacement procedure on the patient as a result of, for example, disease or trauma. The joint replacement procedure may involve the use of a prosthesis which is implanted into one or more of the patient's bones. In the case of a patella replacement procedure, a orthopaedic prosthesis is implanted into the patient's patella. Specifically, a prosthetic patella component is secured to the patient's natural patella such that its posterior surface articulates with a femoral component during extension and flexion of the knee.
A conventional dome patella component is embodied as a dome-shaped polymer bearing. Other types of patella components include conforming or anatomic bearings which are designed to conform with the bearing surfaces of the femur. Dome patella components allow for greater movement between the patella component and the femoral component of the knee prosthesis, whereas anatomic patella components are more constrained relative to the femoral component.
Both types of patella components have clinical benefits to fit the needs of a given surgical procedure. However, each type of component is generally matched to a specific type of femoral component. In other words, because of the bearing profile of each type of component, they are generally not cross-compatible with a given design of a femoral component.